1. Field of the Invention
The present invention relates to a power source having two independent internal power supplies as back-up power sources, and more particularly, to a power module having multiple levels of redundancy for an electroballistic sequencing system utilized in ejection seat systems of military aircraft.
2. Discussion of the Prior Art
The majority of state of the art ejection seat/canopy sequencing systems utilized in military aircraft are pyrotechnic or ballistic type systems such as hot gas, shielded mild detonated cord and TLX. These ballistic systems are started or activated by the mechanical actuation of a ballistic initiator which creates a super fast ballistic shock wave or signal that travels through a ballistic conduit in a manner analogous to that of an electrical signal through a wire. Although effective, there are a number of disadvantages associated with these types of systems. The two most prominent disadvantages of ballistic systems are system operational lifetime, and ejection sequence timing accuracy, both of which are caused by the inherent characteristics of the system components. Firstly, the chemical constituents utilized in a ballistic device have a fixed lifetime of usefulness, typically 5 to 8 years, and thereafter must be replaced. Accordingly, the system components must be replaced at regular maintenance intervals which is costly in terms of time and money as well as aircraft unavailability. Secondly, ejection sequence timing requires fixed delays; therefore, the ballistic sequence is timed to generate these delays. However, the ballistic initiation is generally based upon some type of chemical reaction and therefore is inherently less accurate than an electrically created time delay.
Recently, ejection seat/canopy sequencing systems are utilizing electroballistic sequencing. These electroballistic systems are started or initiated by turning on an electrical power source. Whereas in a purely ballistic system the chemical constituents must be replaced at regular internals, the components in the electroballistic system, such as cables, plugs, dividers, and resistors, are good for the life of the aircraft, and only a small and accessible portion of the system has to be periodically changed. In addition, as stated above, electrical systems are more accurate in terms of timing as their ballistic counterparts.